“What’s the point of a ballgown unless it’s pouffy? There is no point. Not really. Because an evening dress becomes one only with an element of fantasy. That, and a distinct lack of versatility. It will have to earn its keep in one star-spangled night because it must be so memorable that you can’t wear it again for 20 years.

Grace Kelly founded the ball in 1954 to benefit young artists.

This is Borromeo’s first ball as a member of the Monaco Royal Family; she married Princess Caroline’s son, Pierre Casiraghi this past summer.

Borromeo was arguably the best-dressed attendee at the ball, attended by other members of the family except for Princess Charlene.

Karl Lagerfeld, who was also in attendance, designed the Cuban themed event.